This month, Pathways answers the following question:
What is the correct method for administering and scoring the frequency or pitch pattern test?
The frequency pattern test is a central auditory test whose administration requires a considerable amount of detail. The test administration has undergone some changes since its introduction by Marilyn Pinheiro and Paul Ptacek as an experimental procedure in the early 1970s.
In explaining how to administer this test, it is probably best to take it step by step, so that is what I will do. First, however, some basics about the test. The frequency pattern test (on CD) consists of 880-Hz (low) and 1122-Hz (high) tones that are 200 msec in duration, have an interstimulus interval of 150 msec, and a 10-msec rise fall time.
A TEN-STEP PROCESS
Now let's look at how this test is administered/scored:
- It is important to be face-to-face with the patient when explaining the directions of this test.
- Explain that the patient will be hearing three successive tones. Each tone will be either high-pitched or low-pitched. At this point, give both visual and acoustic examples of what high and low pitch are by voicing examples or by giving examples through the speaker in the sound room. It is critical that children understand the meaning of high and low before you start.
- Next, provide some examples of patterns by voicing them and also providing a visual cue or visual display of the pattern.
- After you are sure the patient understands the task with both acoustic and visual examples, drop the visual example and provide practice on only the auditory. It is important to understand that at this point the patient may understand the task but begin missing the patterns. Some individuals with very poor pattern perception cannot do the task without the visual cues. It is important when voicing the pattern to exaggerate high and low and to speak relatively slowly so the pattern is easy to perceive.
- When you are sure the patient understands the task, move into the control room and administer six or seven practice items from the actual test through earphones or the speaker. Again, the patient may miss these items and still understand the task. Once you feel comfortable with the responses, start the test.
- The test is usually administered at 50 dB HL, but this is not critical. Remember that the frequency pattern test reaches maximum performance around 10–15 dB SL in regard to hearing thresholds at 1000 Hz. We have shown no difference in performance of normals at either 20 dB SL or 50 dB SL.
- Allow as much time as necessary for the patient to respond to the pattern. The CD version/tape has either a 5- or 7-second inter-pattern interval. This is usually sufficient for the patient to respond. However, in some cases it may be necessary to stop the CD to provide more time.
- In scoring the test items, several factors should be kept in mind. First, the pattern should not be repeated unless the patient was not given a fair chance to hear the pattern. If the patient provides four elements rather than three, even if the first three are correct, the pattern is incorrect, for example, HHLL for HHL.
There are several modes of responses: verbal (repeat the pattern), humming the pattern, or pointing to high and low visual displays. If an individual scores poorly using a verbal report, it may be worthwhile asking him to hum the pattern. Some patients can do well humming the pattern but not reporting it verbally. This indicates difficulty in transferring from right to left hemisphere or a problem in the left hemisphere.
I believe that everyone should develop his or her own norms; however, here are ours:
- When a patient reverses a pattern, (e.g., responds LHL when the pattern is HLH), it is incorrect. Originally, reversals were not considered wrong. However, later we demonstrated that some patients with central pathology had numerous reversals. In such cases, if reversals had been considered correct, the patients would have passed.
- If the test is administered under phones, 30 patterns are given to each ear. If the patient misses 14 or 15 of the first 15 items or gets 14 or 15 correct, the test can be stopped. If the test is administered in a sound field, 40 items should be given. If 18 or more of the first 20 are missed or are correct, the test can be stopped.
Musiek F, Pinheiro M, Wilson D: Auditory pattern perception in split-brain patients. Arch Otolaryngol
Musiek F: Frequency (pitch) and duration pattern tests. JAAA
Musiek FE, Pinheiro ML: Frequency patterns in cochlear, brainstem, and cerebral lesions. Audiology